Bacterial detection cartridge

ABSTRACT

Described herein are methods and apparatus for rapid detection of microorganisms in biological samples (e.g. blood) for analysis to determine the presence or absence of infectious microorganisms in the samples. The apparatus includes a cartridge with a lid and a tray, a mechanism for isolating a bulk sample into multiple smaller samples, and a sensor disposed on the tray to determine the presence or absence of microorganisms. The cartridge lid includes projections that, in a first position, allow for sample to distribute evenly in the cartridge tray and, in a second position, isolate the sample into multiple smaller volume samples. The apparatus and method shorten the time-to-detection of a microorganism in a sample and reduce the steps required from sample collection to microorganism detection.

BACKGROUND OF THE INVENTION

Sepsis is a significant healthcare issue due to its high frequency ofoccurrence and high mortality rate in hospitals. Sepsis is characterizedby a whole-body inflammatory state, called a systemic inflammatoryresponse (SIRS), and by the presence of a known or suspected infection.The immune system may cause this inflammatory response as a consequenceof microbes in the blood, urine, lungs, skin, or other tissues, forexample. One of the leading causes of sepsis is a bloodstream infection(BSI). BSI is most commonly diagnosed by a blood culture, in which asample of blood is incubated with a medium in an atmosphere controlledto promote bacterial growth.

Current automated blood culture systems can take 12-48 hours to detectthe presence of infectious microorganisms in blood and can take up to 5days to rule out the presence of any infectious microorganisms. It cantake up to another 12-48 hours to identify the infectious microorganismsby sub-culturing the positive blood culture and performingidentification and antimicrobial susceptibility tests. These results canbe too late to alter the treatment course and result in the death of thepatient.

One approach to faster bacterial time to detection (“TTD”) is dividingthe sample liquid together with growth media into a large number ofsmaller volume samples that are contained in closed small volumecompartments (see U.S. Pat. Nos. 5,770,440 and 5,891,739 to Berndt, theentire contents of which are both hereby incorporated by referenceherein). The added steps required to segregate the blood/media sampleinto smaller volume samples can be difficult and time consuming.Additionally, designing a product to address this increased workflow canbe limited by considerations of manufacturability and cost.Consequently, a small-volume compartment BSI product design that is easyto manufacture, cost effective, less time-consuming to use and reducesTTD in a clinical sample is desired.

BRIEF SUMMARY OF THE INVENTION

Described herein are methods and apparatus for rapid detection ofmicroorganisms in biological samples (e.g. blood) for analysis todetermine the presence or absence of infectious microorganisms in thesamples. The apparatus includes a cartridge with a lid and a tray, amechanism for isolating a bulk sample into multiple smaller samples, anda sensor disposed on the tray to determine the presence or absence ofmicroorganisms.

According to the methods described herein, the cartridge lid isassembled onto the cartridge tray in a first position, the sampleintroduced into the cartridge tray and allowed to distribute across thevolume of the cartridge tray, and the cartridge lid is moved into asecond position creating a plurality of compartments isolating the bulksample into multiple samples of a smaller volume. The method andapparatus allow for, inter alia, a reduced time-to-detection formicroorganisms in a biological sample and obviates the need to manuallydispense a sample into individual compartments of a detection device.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a perspective view of one embodiment of a portion of a topand bottom lid portion of a cartridge lid.

FIG. 2 shows a perspective view of the top and bottom lid portions ofFIG. 1 assembled together.

FIG. 3 shows a perspective view of a portion of a cartridge tray.

FIG. 4 shows a perspective view of the cartridge lid assembly of FIG. 2mated to the cartridge tray of FIG. 3 in a first position.

FIG. 5 shows a perspective view of the cartridge lid assembly of FIG. 2mated to the cartridge tray of FIG. 3 in a second position.

FIG. 6 shows a perspective view of the entire top portion of thecartridge lid shown in FIG. 1.

FIG. 7 shows a perspective view of the entire bottom portion of thecartridge lid shown in FIG. 1.

FIG. 8 shows a perspective phantom view of the top and bottom portionsof the cartridge lid shown in FIGS. 6 and 7 prior to assembly.

FIG. 9 shows a perspective phantom view of the top and bottom portionsof the cartridge lid shown in FIG. 8 assembled.

FIG. 10 shows a perspective view of the entire cartridge tray shown inFIG. 3.

FIG. 11 shows a side plan view of the cartridge lid assembly andcartridge tray shown in FIG. 8 prior to assembly.

FIG. 12 shows a side plan view of the cartridge lid and cartridge trayassembled in a first position, with an enlarged view of mating features.

FIG. 13 shows the steps of collecting a blood sample.

FIG. 14 shows a side view of a sample being introduced into thecartridge lid and tray in the first position.

FIG. 15 shows a side view of the cartridge lid and tray transitioningfrom a first position to a second position.

FIGS. 16A-B show air escaping the cartridge tray during the transitionfrom the first position to the second position.

FIG. 17 shows a schematic view of the cartridge undergoing bacterialdetection.

FIG. 18 shows a top plan view of an alternate embodiment of thecartridge lid assembly shown in FIG. 9 with enlarged views of individualcompartments.

FIG. 19 shows a side plan view of an alternate embodiment of thecartridge lid and cartridge tray of FIG. 13 assembled in a firstposition.

FIG. 20 shows a side plan view of the cartridge lid and cartridge trayof FIG. 20 filled with sample and oil.

FIG. 21A shows a top plan view of an alternate embodiment of a cartridgelid and tray in a first position.

FIG. 21B shows a top plan view of the cartridge lid and tray of FIG. 21Ain a second position.

FIG. 22A shows a top plan view of an alternate embodiment of a cartridgelid and tray in a first position.

FIG. 22B shows a top plan view of an alternate embodiment of a cartridgelid and tray in a first position.

FIG. 23 shows a perspective phantom view of a bacterial detectioncartridge with portions omitted according to one embodiment of theinvention.

FIG. 24 shows a sectional view of the cartridge of FIG. 23 along adiameter of the cartridge.

FIGS. 25A-B show a sectional view of the cartridge of FIG. 23 during andafter sample introduction, respectively.

FIG. 26A shows a sectional view of the filled cartridge of FIG. 25B in asecond position.

FIG. 26B shows the filled cartridge of FIG. 26A after vents are sealed.

FIG. 27 shows two cartridges of the type illustrated in FIG. 24 in astacked configuration.

DETAILED DESCRIPTION

Referring generally to FIGS. 1-5, a bacterial detection cartridge 10according to an embodiment of the invention generally includes acartridge lid assembly 16 and a cartridge tray 18. The cartridge lidassembly 16 is composed of a top lid portion 12 and a bottom lid portion14 which can be made separately, for example via injection-molding, andsnapped together to form the cartridge lid assembly 16. The cartridgelid assembly 16 is then positioned onto the cartridge tray 18 in anelevated first position (FIG. 4). The cartridge lid assembly 16 can thenbe pushed down to lock the bacterial detection cartridge 10 into asecond position (FIG. 5) after sample 66 (FIG. 16) has been introducedinto the cartridge tray 18 through a sample injection port 20 (FIG. 1)defined in top lid portion 12. In one embodiment, the bacterialdetection cartridge 10 containing the sample 66 is made ready for sampleincubation. All compartments 24 are configured to allow for sampleremoval when the tray is in the second position. Therefore, anycompartment 24 with sample 66 for which a positive detection result wasobtained can be accessed for sample removal for further analyses.

Referring generally to FIGS. 1-2, the cartridge lid assembly 16 includesa top lid portion 12 and a bottom lid portion 14. The top lid portion 12includes multiple top lid access apertures 22 positioned near the centerof each compartment 24 of the bottom lid portion 14. The top lid accessapertures 22 allow a pipette, syringe or other device to access thesample 66 within a selected compartment 24. The top lid access apertures22 are integrated into the top lid 12 as thin circular areas. A sampleinjection port 20 is formed in the top lid portion 12 to allow a sample66 to be introduced into the cartridge tray 18. The port is configuredto allow sample introduction into the lid assembly via a syringe orother sample introduction device. A separate re-sealable pressureescaping outlet 42 is also built onto the top lid portion 12 (shown inFIGS. 6-12).

The bottom lid portion 14 defines the compartments 24 in cooperationwith the cartridge tray 18. Specifically, each compartment 24 is definedby four downward projecting side-wall portions 24 a-d in the bottom lidportion 14, the top wall 24 e of the bottom lid portion 14, and thecartridge tray 18. In other words, the bottom lid defines a grid ofcompartments 24 except for the bottom surface of the compartments, whichis defined by the cartridge tray 18. The bottom lid portion 14 alsoincludes multiple bottom lid access apertures 26 positioned in theillustrated embodiment near the center of each compartment 24 andaligned with a corresponding top lid aperture 22. The alignment of thetop lid access apertures 22 with the bottom lid access apertures 26permit an access device, such as a pipette or syringe, to penetratethrough both the top lid portion 12 and bottom lid portion 14 to accessthe compartment 24 underneath. Also included on the bottom lid portion14 are vents 28 for each compartment 24. The vents 28 align with theseal rods 30 on the cartridge tray 18.

The top lid access apertures 22 can be covered with a pressure sensitiveadhesive foil 72 (shown in FIG. 18) to isolate the interior of thebacterial detection cartridge 10 from the environment. In use, after anaccess device penetrates the top and bottom lid portions 12, 14 toaccess the compartment 24, the top lid access apertures 22 may bere-sealed, for example with an additional layer of pressure sensitiveadhesive foil 72, to again isolate the interior of the cartridge 10 fromthe environment to provide for safe handling, including disposal and/orautoclaving. In addition to reducing chances of contamination, providinga seal keeps sample components within the compartment 24. For example,without a seal, CO₂ could escape from the compartment 24, causing thesensor 36 (described below) to report inaccurate results of bacterialmetabolism. Similarly, the bottom lid access apertures 26 may initiallybe sealed by a material, such as a pressure sensitive adhesive foil (notillustrated). A seal on the bottom lid access apertures 26 isolates thecontents of a particular compartment 24 from the headspace between thetop lid portion 12 and bottom lid portion 14 when the cartridge lidassembly 16 is in the second position, described more fully below.

Referring generally to FIGS. 3-5, the cartridge tray 18 is a tray withseal rods 30 and an interior open vessel 32 built on the surface. Thevessel 32 is configured to receive reagents such as resin gel pellets34. The seal rods 30 function to guide the cartridge lid assembly 16 onto the cartridge tray 18, and serve to seal the vents 28 of thecompartments 24 when the cartridge lid assembly 16 is moved from thefirst position to the second position. In one embodiment, the vessel isa raised rim on the surface of the cartridge tray 18. In otherembodiments, the resin gel pellets 34 can be applied directly to thecartridge tray without the use of vessels 32. The exact location and thenumber of the vessels 32 and seal rods 30 are determined by thearrangement of the compartments 24 on the bottom lid portion 14 and islargely a matter of design choice. The cartridge tray 18, top lidportion 12, and bottom lid portion 14 can be made of various materials,such as clear polypropylene or similar optically clear plastic resinssuch as, but not limited to, polycarbonate, cyclic olefin polymer, andpolystyrene. Although it is preferred that the top lid portion 12 andbottom lid portion 14 are a transparent material, other non-transparentmaterials are contemplated for use in the assembly described herein.

In one embodiment, the cartridge tray 18 is preloaded with biosensorcoating 36 on the bottom surface 37 outside the area of the interioropen vessels 32. Although a biosensor coating 36 is preferred for thesensor, other sensors known in the art can be used without deviatingfrom the scope of the invention. The sensor 36 can detect, for example,O₂ and/or CO₂ changes collectively or independently (see U.S. Pat. No.6,989,246 to Yeh, the entire contents of which are hereby incorporatedby reference herein). Antimicrobial adsorption resin gel pellets 34 aredispensed inside the interior open vessels 32. The resin gel pellet ismade of, for example, antimicrobial adsorption resins mixed withwater-soluble materials for ease of dispensing and resin releasecapability in aqueous environment. Such resins are known in the art. Forexample, U.S. Pat. No. 5,624,814 to Waters et al. describes resins addedto culture media to isolate microorganisms from substances that have thepotential to inhibit the growth of the microorganisms. Other referencesthat contemplate combining a resin with a biological sample to removegrowth inhibitors from a biological sample suspected of containing atarget microorganism include U.S. Pat. Nos. 4,145,304 and 4,174,277,both to Melnick et al. The entire contents of these references are eachhereby incorporated by reference herein.

Referring to FIGS. 6 and 7, the top lid portion 12 and bottom lidportion 14 also include snap post apertures 38 and snap posts 40,respectively, to allow the top lid portion to snap into the bottom lidportion 14 to form the cartridge lid assembly 16, as illustrated in FIG.2.

As noted previously, once the cartridge lid assembly is positioned ontothe cartridge tray 18 in the second position, a grid of segregatedcompartments 24 is formed. Vents 28 and pressure escaping outlet 42maintain desired compartment conditions during the sample injectionprocess and “push-down” action of the cartridge lid assembly 16 onto thecartridge tray 18. Vents 28 allow the pressure among the compartments toequilibrate. Pressure escaping outlet 42 is configured to allow thebacterial detection cartridge 10 to vent if pressure builds up above apredetermined threshold.

The seal rods 30 on the cartridge tray 18 are located such that eachcompartment 24 is adjacent to at least one seal rod 30. The seal rod 30in each compartment 24 aligns with the vent 28 of the bottom lid portion14. The seal rod 30 has a diameter that permits the seal rod 30 to fitwithin the vent 28. The length of the seal rod 30 is such that, when thecartridge lid assembly 16 is in the second position, the seal rod 30 onthe cartridge tray 18 seals the vent 28. This is illustrated in FIGS.16A-B. The pressure escaping outlet 42 on the top lid portion 12 is keptopen during sample injection and pushdown operation. Note that pressureescaping outlet 42 in top lid portion 12 overlies opening 43 in bottomlid portion 14 to permit pressure release through the bottom lid portion14. Pressure escaping outlet 42 is then re-sealed for incubation of theloaded bacterial detection cartridge 10. This may be accomplished, forexample, with the use of a re-sealable foil 45.

Referring generally to FIGS. 6-10, various aspects of the bacterialdetection cartridge 10 in accordance with an embodiment of the inventionare illustrated including top lid portion 12, bottom lid portion 14, ofthe cartridge lid assembly 16, and cartridge tray 18.

As illustrated in FIGS. 6-9, the sample injection port 20 comprises asample injection aperture 19 in the top lid portion 12 that aligns witha septum 21. The septum 21 sits in a septum compartment 23 formed in thebottom lid portion 14.

Other features illustrated in FIGS. 6-10 that are not illustrated inFIGS. 1-5 include the pressure escaping outlet 42 previously described,raised block 44, and raised inlet sample distributor 46. As describedabove, the pressure escaping outlet 42 allows for pressure equalizationduring sample introduction and as the cartridge lid assembly 16 is movedfrom the first position to the second position. The bottom lid portion14 also contains an open portion 43 that aligns with the pressureescaping outlet 42 in the top lid portion 12 to allow for pressure toescape from the bacterial detection cartridge 10 through pressure outlet42. The pressure escaping outlet 42, 43 is kept open as the cartridgelid assembly 16 is pushed down into the first and second positions onthe cartridge tray 18. Once in the second position, the pressureescaping outlet 42 is re-sealed. The raised block 44 aligns with thepressure escaping outlets 42, 43. The raised block 44 prevents samplefrom flowing into the area occupied by the raised block. If there weresample 66, resin gel 34 and sensor 36 in a compartment 24 instead of theraised block 44, the entire sample 66 in the compartment 24 beneath thepressure escaping outlet 42, 43 would be exposed to the entire headspacebetween the top lid portion 12 and bottom lid portion 14 because of openportion 43. This headspace could hinder bacterial detection, so theraised block 44 is preferred.

The cartridge tray 18 also contains a raised inlet sample distributor46. The raised inlet sample distributor 46 is in fluid communicationwith the sample injection port 20. As sample 66 is introduced by asyringe or other device, the sample 66 flows across the surface of theinlet sample distributor 46 in all directions into the cartridge tray18. This ensures more uniform sample distribution in the cartridgeassembly as it fills with sample

Referring generally to FIGS. 11-18, the steps by which the bacterialdetection cartridge 10 according to an embodiment of the invention isassembled and filled are illustrated. The bacterial detection cartridge10 is illustrated in side and side perspective views in these figures.The first step is to snap the top lid portion 12 into the bottom lidportion 14 to form the cartridge lid assembly 16. The cartridge tray 18is also prepared by inserting resin gel 34 into the vessels 32 of thetray cartridge and further by depositing the biosensor coating 36 on thesurfaces previously described. The assembly steps may be completed bythe manufacturer, rather than the end user. In such embodiments, theuser begins with a pre-assembled cartridge lid 16 and cartridge tray 18.Assembly by a manufacturer is preferred as the bacterial detectioncartridge 10 is preferably sterilized and in the first position whenprovided to a user.

The user then assembles the bacterial detection cartridge 10 into itsfirst position, as shown in FIG. 12, by pressing down the cartridge lidassembly 16 partially onto the cartridge tray 18. As mentioned above,this step is preferably performed by a manufacturer so that thecomponents are sterilized and in the first position when provided to theuser, but user assembly is still within the scope of the invention. Thecartridge lid assembly 16 and cartridge tray each include features tolock them together. Failure to lock indicates that the cartridge lidassembly 16 and cartridge tray 18 are not in proper engagement. Thelocking features may include multiple locking features, such asprotrusions and corresponding recesses, such that the cartridge lidassembly 16 and the cartridge tray 18 can lock in multiple discretestages. Locking features may be, for example, sawteeth 47 on thecartridge lid assembly 16 and notches 48 on the cartridge tray 18. Thesawteeth 47 and notches 48 are configured in the illustrated embodimentto allow the cartridge lid assembly 16 to engage and lock on thecartridge tray 18 in the first and second positions. The sawteeth 47initially snap in to the notches 48 in the first position, after whichthe cartridge lid assembly 16 can be further advanced to snap thesawteeth 47 into an additional set of notches 48 to move the bacterialdetection cartridge 10 into the second position.

Sample preparation is illustrated in FIG. 13. The sample 66 may becollected, for example, directly from the patient into syringe 50 orsimilar device pre-filled with growth media 56 and under a partialvacuum balanced with nitrogen or other preferred gas compositions forstorage stability. In one embodiment, the syringe 50 can contain oil,described more fully below. A traditional butterfly needle 52 can beused with a first end located at the sample source in the patient 54(e.g. in a vein) and with a second end connected to a needle in thesyringe 50. A plunger 58 and needle 60 are then connected to the syringe50 for injecting the sample 66 into the bacterial detection cartridge10. The collection step may alternatively include multiple steps,wherein the sample is first collected from the patient, undergoes somesort of pre-processing, and is then introduced into the bacterialdetection cartridge 10 via the collection tube. The sample 66 is notlimited to blood, and can be any other biological sample such as spinalfluid, urine, saliva, etc.

When the bacterial detection cartridge 10 is in the first position, thespacing between the bottom lid portion 14 and the cartridge tray 18 issuch that sample 66 will flow across the cartridge tray 18 andrelatively uniformly fill a portion of each compartment 24 asillustrated in FIG. 15. Sample 66 will not flow into the region occupiedby raised block 44. The user pierces the septum 21 in the sampleinjection port 20 with the needle 60 on the syringe 50, and depressesthe plunger 58 to inject the sample 66 into the bacterial detectioncartridge 10. Because the bacterial detection cartridge 10 is in thefirst position, the sample 66 can flow freely across the bottom ofcartridge tray 18, with uniform distribution of sample being assisted bythe raised inlet sample distribution guide 46, as shown in FIG. 14.During sample injection, the re-sealable foil 45 on the pressureescaping outlet 42 is in the open position, allowing for the pressureinside the bacterial detection cartridge 10 to equalize with thepressure outside the bacterial detection cartridge 10. A cartridge andsyringe docking station 62 may optionally be employed to provideadditional stability to the bacterial detection cartridge 10 and toprovide a guide for the syringe 50. Automated robotic systems forproviding sample to the compartments are contemplated.

After the sample 66 is fully injected and after the sample volume hasequilibrated among the compartments (the skilled person would appreciatethat the “self-leveling” aspect of the distribution of sample within thetray is best achieved when the tray is in a level position), the useradvances the cartridge lid assembly 16 on the cartridge tray 18 untilthe sawteeth 47 engage the next set of notches 48, moving the bacterialdetection cartridge 10 to the second position, as shown in FIG. 15.Although not specifically described herein, the assembly is easilyconfigured to provide one or more intermediate positions.

Referring to FIGS. 16A-B, as the cartridge lid assembly 16 is advancedfrom the first position to the second position, the seal rods 30 advancefurther into the vents 28, sealing them. Before the downward projectingwalls 24 a-d of the compartment 24 come into contact with the sensor 36disposed on the cartridge tray 18 surface, air 64 escapes through thevent 28. As the downward projecting walls 24 a-d of the compartment 24advance onto the sensor 36 on the cartridge tray 18, the seal rods 30simultaneously plug the vents 28. Once the downward projecting walls 24a-d of the compartment 24 touch the cartridge tray 18, the sample 66 issealed into multiple compartments 24. The re-sealable foil 45 is thenre-sealed to isolate the sample inside the bacterial detection cartridge10 from the environment. If desired, gaskets in the form of tapes can beused to seal between the cartridge lid assembly 16 and cartridge tray 18to prevent potential leaks.

Once the sample 66 is loaded into the bacterial detection cartridge 10and sealed, the cartridge is placed into an incubator 70 to growmicroorganisms in the sample. The sensor 36 detects growth, for exampleby detecting changes in concentration of O₂ and/or CO₂ from increasedlevels of bacterial metabolism, and reports each compartment 24 thattests positive for growth. As such detection techniques are well knownin the art, they are not described in further detail herein. Ultrasoundor similar mechanisms can be used to agitate the bacterial detectioncartridge 10 during inoculation.

As shown in the embodiment illustrated in FIG. 18, the compartments 24of the bacterial detection cartridge 10 are arranged in a grid format,with each compartment including identifiers. For example, thecompartments can include a row-identifying letter and column-identifyingnumber (G3, G4, H3, H4 etc.). Each compartment 24 that tests positivefor bacterial growth by the incubator 70 is reported to the user. If anycompartment 24 shows signs of bacterial growth, there is often a needfor removal of the sample 66 from those compartments 24 forpost-processing procedures such as identification or antibioticsusceptibility testing. The user identifies the specific compartment(s)24 testing positive for bacterial growth, inserts a removal device suchas a syringe or pipette into the desired compartment via the top andbottom lid access apertures 22, 26 respectively, piercing any adhesivefoils or film 72 covering the apertures, and withdraws the positivesample 66. The user then may perform desired post-processing of thepositive sample to, for example, identify the bacteria in the bloodsample 66. One, some, or all of the above-mentioned steps may beautomated. The bacterial detection cartridge 10 is not limited to around dish, but can be other shapes including, but not limited to, ovalor other polygons.

An alternate embodiment of the bacterial detection cartridge 10 is shownin FIGS. 19-20. In this embodiment, the top lid portion 12 and cartridgetray 18 are substantially similar to embodiments previously described.The top of the bottom lid portion 14, in the illustrated embodiment, isdownwardly deflected towards the center of each compartment 24. Thisdownward deflection 74 provides a guiding mechanism for insertion of anaccess device, such as a syringe or pipette. The downward deflection 74further provides a barrier from the sample 66 escaping if anysplash-back occurs during manipulation of the bacterial detectioncartridge 10. Additionally, if a portion of sample 66 sticks to the topsurface of the bottom lid portion 14, for example while transportingbacterial detection cartridge 10, the downward deflection 74 provides apath for the sample to flow down into the compartment 24. This may beespecially useful considering the small volumes of sample 66 in eachcompartment 24.

FIG. 20 shows another embodiment of the invention. Syringe 50 (FIG. 13)is prepackaged with oil, for example mineral oil, in addition to growthmedia 56. The sample 66 with growth media 56 and oil is loaded into thebacterial detection cartridge 10 as described above. Once loaded, thelow density and low miscibility of the oil causes the oil to migrate tothe upper surface of the sample 66, creating an oil layer 76. Otherfluids can be used besides mineral oil, including, but not limited to,silicone oil and organic polymers. The oil layer 76 acts as a seal toisolate the sample 66 from the environment external to the oil layer 76.This fluid seal can be used alternatively, or in addition to, sealablematerials such as the adhesive foils described above.

The operation of the bacterial detection cartridge 10 with two stages ofpushing into a first and second position can be functionally replacedwith alternate mechanisms. For example, a twist-down mechanism, or aslide-over mechanism, as shown in FIGS. 21A-B and 22A-B, can be usedwith a similar result. Referring to FIG. 21A, a top-down view of thebacterial detection cartridge 10 is shown. The cartridge tray includesvessels 32 as described above and additionally includes posts 80. Thebottom lid portion 14, in the illustrated embodiment, has downwardprojecting walls 82. The cartridge lid assembly 16 is placed onto thecartridge tray 18 in a first position, shown in FIG. 21A, in which thewalls 82 and posts 80 do not form a completely isolated compartment 24.This is functionally similar to the first position described above, inwhich sample 66 may be introduced to the bacterial detection cartridge10 and flow uniformly therethrough. Once the sample 66 has beenintroduced, the cartridge lid assembly 16 can be translated into asecond position, illustrated in FIG. 21B. In the second position, thewalls 82 and posts 18 are positioned to isolate each compartment 24,including the sample 66 therein. The specific shapes of the describedcomponents can vary, based on design choices, while accomplishing asimilar result. For example, FIGS. 22A-B show yet another embodiment ofthe slide-over mechanism, except the posts 80 a are rectangularprojections instead of triangular projections as in FIGS. 21A-B. Thewalls 82 a shown in FIGS. 22A-B are shaped to correspond to theprojections 80 a such that the cartridge lid assembly 16 can be slidfrom a first position (FIG. 22A) in which sample 66 can freely flow to asecond position (FIG. 22B) in which compartments 24 isolate the sample.

A further embodiment of a bacterial detection cartridge 100 isillustrated in FIG. 23. In this embodiment, bacterial detectioncartridge 100 is a circular disk with a plurality of radially extendingwalls 101. A plurality of compartments 124 are created by the walls 101in combination with the bacterial detection cartridge 100, eachcompartment being defined by two adjacent walls 101 and the top, bottom,and side walls of the bacterial detection cartridge. FIG. 23 illustratesa 32 compartment embodiment, with half of the compartments omitted forclarity of illustration. The top wall of each compartment 124 includes avent aperture 128, providing a venting mechanism as discussed below. Thevent apertures 128 may act additionally as access apertures for apipette or other withdrawal tool to withdraw sample 166 from thecorresponding compartment 124. Alternatively, each compartment 124 mayinclude a separate access aperture (not illustrated) in addition to theventing apertures 128.

As illustrated in FIG. 24, each compartment 124 is preloaded withbiosensor coating 136 on the bottom surface. The biosensor coating 136may be provided in an annular pattern on the bottom surface of thebacterial detection cartridge 100, or in other configurations. Althougha biosensor coating 136 is preferred for the sensor, other sensors knownin the art can be used without deviating from the scope of theinvention. Each compartment further includes a vessel 132 configured toreceive reagents such as resin gel pellets 134. In one embodiment, thevessel is a raised rim on the bottom surface of the bacterial detectioncartridge 100. In other embodiments, the resin gel pellets 134 can beapplied directly to the bottom surface of the bacterial detectioncartridge without the use of vessels 132.

A plunger 190 is provided near the center of the bacterial detectioncartridge above a raised inlet sample distributor 146. The plunger 190has an open first position, as illustrated in FIG. 24. In the firstposition, the space between the plunger 190 and the raised inlet sampledistributor 146 creates a flow channel 192. As sample 166 is introducedinto the bacterial detection cartridge 100 when the plunger 190 is inthe first position, the sample flows via the flow channel 192 into thecompartments 124. The plunger 190 includes a septum 121 to facilitateintroduction of sample 166.

Sample preparation is similar to that discussed with reference to FIG.13. Once the sample 166 is prepared, it is injected, for example usingsyringe 150, through septum 121, flows through the flow channel 192, andfills the compartments 124, as illustrated in FIGS. 25A-B. During sampleintroduction, vent apertures 128 are open to allow pressureequalization.

Once the sample 166 has been introduced, as illustrated in FIG. 25B, theplunger 190 is moved to the closed second position, as illustrated inFIGS. 26A-B. The user presses the plunger 190 in direction D to closethe plunger in the second position. The bacterial detection cartridge100 includes snap locks 198 to lock the plunger 190 in the secondposition. The bacterial detection cartridge 100 includes one or moreapertures 194 located above the plunger 190. These apertures 194 allowfor pressure equalization to facilitate transition of the plunger 190from the first position to the second position. Once the plunger 190 isin the second position, the flow channel 192 is sealed off, and eachcompartment 124 with sample 166 is sealed off to the environment withthe exception of vent apertures 128. After the plunger 190 has beenmoved to the second position, the vent apertures 128 can be sealed, forexample with a re-sealable foil 145. Similarly, the septum 121 can besealed with, for example, a re-sealable foil 196. Once the sample 166has been fully introduced, the plunger 190 moved to the second position,and the vent apertures 128 sealed, the bacterial detection cartridge 100can be placed into an incubator. The growth of organisms inside thebacterial detection cartridge 100, as well as detection, removal, andprocessing is substantially similar to the procedures described withother embodiments above. The shape of the bacterial detection cartridge100 allows for multiple cartridges to be stacked, as shown in FIG. 27,for easier storage and transportation.

Although the invention herein has been described with reference toparticular embodiments, it is to be understood that these embodimentsare merely illustrative of the principles and applications of thepresent invention. It is therefore to be understood that numerousmodifications may be made to the illustrative embodiments and that otherarrangements may be devised without departing from the spirit and scopeof the present invention as defined by the appended claims.

1. An apparatus for determining the presence of a microorganism in asample, the apparatus comprising: a container lid having a plurality ofsets of downward projecting walls; a container tray adapted to receive asample and to be assembled with the container lid in a first positionand a second position; wherein, when in the first position, compartmentsdefined by the sets of downward projecting walls in the container lidare open to each other thereby permitting the sample to flow fromcompartment to compartment within the container tray; wherein, when inthe second position, the compartments are sealed off from each other,each sample portion being confined to its respective compartment, eachcompartment being defined by one set of downward projecting walls, thecontainer lid from which the downward projecting walls extend, and thecartridge tray.
 2. The apparatus of claim 1, wherein at least onecompartment includes a sensor configured to detect at least one of thepresence, absence or growth of a microorganism.
 3. The apparatus ofclaim 2, wherein the sensor is a biosensor coating applied to thecontainer tray.
 4. The apparatus of claim 1, wherein at least onecompartment includes a vessel projecting upward from a surface of thecontainer tray.
 5. The apparatus of claim 4, wherein the vessel of theat least one compartment is at least partially filled with a resin gel.6. The apparatus of claim 1, further comprising a plurality of rodsprojecting upwardly from the cartridge tray and a plurality of ventapertures formed in the container lid, wherein the vent apertures areadapted to receive the respective rods, and allow the rods to advanceinto the vent apertures, the rods being dimensioned to seal therespective vent apertures when fully advanced therein.
 7. The apparatusof claim 6, wherein the container lid comprises projections having anirregular surface configured to conform to an irregular surface oncartridge tray sidewalls, the corresponding irregularities allowing thecontainer lid to lock on the cartridge tray in a first lockingconfiguration and to be advanced to lock on the cartridge tray in asecond locking configuration.
 8. The apparatus of claim 7, wherein theirregular surface of the lid is a plurality of sawteeth and theirregular surface of the cartridge tray is a plurality of notches. 9.The apparatus of claim 6, wherein the rods are fully advanced into thevent apertures when the container lid advances from a first lockedconfiguration to a second locked configuration.
 10. The apparatus ofclaim 1, further comprising a pressure vent formed in the container lidand a raised block formed in the container tray, the pressure ventaligning with the raised block, such that, when the container tray isassembled with the container lid in the second position, the raisedblock closes the vent.
 11. The apparatus of claim 10, further comprisinga re-sealable foil covering the pressure vent.
 12. The apparatus ofclaim 1, wherein the container lid comprises a plurality of accessapertures, at least one of the access apertures aligning with arespective compartment, the at least one access aperture being adaptedto receive an access device therethrough to remove sample from therespective compartment.
 13. A method for determining the presence of amicroorganism in a sample, the method comprising the steps of: providinga container lid with a plurality of sets of downward projecting walls;providing a container tray with one or more sensors, the container traybeing adapted to be assembled with the container lid such that thedownward projecting walls define a plurality of compartments in thecontainer tray and at least one of each of the one or more sensors isdisposed in each of at least a portion of the plurality of compartmentsand wherein, in the first position, the compartments defined by thedownward projecting walls are open to each other; assembling thecontainer lid to the container tray in a first position; introducing asample into the assembly; moving the assembly from the first position toa second position wherein in the second position, the compartments areclosed to each other and sample portions in each compartment areisolated from each other; and interrogating the sensor to determine atleast one of the presence or the absence of a microorganism in thesample or, if a microorganism is present, its response to a condition ora reagent to which the sample is subjected.
 14. The method of claim 13,wherein the step of assembling the container lid to the container trayin the first position further comprises conforming projections of thecontainer lid having an irregular surface to an irregular surface oncartridge tray sidewalls, such that the container lid locks on thecartridge tray in a first locking configuration.
 15. The method of claim14, wherein the step of moving the assembly from the first position tothe second position further comprises advancing projections of thecontainer lid to conform to the irregular surface on the cartridge traysidewalls in a second locking configuration.
 16. The method of claim 13,wherein the step of moving the assembly from the first position to thesecond position further comprises advancing at least one rod projectingupwardly from the container tray into sealed engagement with acorresponding vent aperture in the container lid.
 17. An apparatus fordetermining the presence of a microorganism in a sample, the apparatuscomprising: a container assembly having a top, a bottom, an inner sidewall, an outer side wall, a plurality of walls extending radially fromthe inner side wall to the outer side wall defining a plurality ofcompartments, and a plunger device adapted to move from a first positionto a second position, wherein, when in the first position, the plungerdevice defines a flow pathway adapted to receive a sample, the flowpathway being in fluid communication with an exterior of the containerassembly and also with the plurality of compartments; wherein, when inthe second position, the plunger device seals the flow pathway, suchthat the plurality of compartments are not in fluid communication witheach other, and the sample in each of the plurality of compartments isisolated from the sample in other compartments.
 18. The apparatus ofclaim 17, further comprising a plurality of sensors positioned on thebottom of the container assembly, each of the plurality of sensors beingconfigured to detect at least one of the presence, absence or growth ofa microorganism.
 19. The apparatus of claim 17, further comprising abiosensor coating applied to the bottom of the container assembly, thebiosensor coating being configured to detect at least one of thepresence, absence or growth of a microorganism.
 20. The apparatus ofclaim 17, further comprising a plurality of vessels projecting upwardlyfrom the bottom of the container assembly, each one of the plurality ofvessels present in a corresponding one of the plurality of compartments.21. The apparatus of claim 20, wherein each of the plurality of vesselsis at least partially filled with a resin gel.
 22. An apparatus fordetermining the presence of a microorganism in a sample, the apparatuscomprising: a container lid having a top surface and a plurality ofwalls projecting downward from the top surface; a container tray havinga bottom surface and a plurality of posts projecting upward from thebottom surface, the container tray being adapted to receive a sample andto be assembled with the container lid in a first position and a secondposition; wherein, when in the first position, compartments defined bythe top surface of the lid, the bottom surface of the container tray,the plurality of downward projecting walls, and the plurality of upwardprojecting posts, are open to each other thereby permitting the sampleto flow from compartment to compartment within the container tray;wherein, when in the second position, the compartments are sealed offfrom each other, each sample portion being confined to its respectivecompartment.
 23. The apparatus of claim 22, wherein each compartment isdefined by the projecting walls, the upward projecting posts, the topsurface of the container lid, and the bottom surface of the containertray.